Assessing the sensing performance of Janus transition metal dichalcogenides (ScSSe, TiSSe and ZrSSe) for oxygencontaining toxic gas molecules such as CO, NO, NO2 and SO2

In this study, the adsorption behavior and sensing capabilities of oxygen-containing gas molecules (CO, NO, NO2, SO2) on Janus ScSSe, TiSSe, and ZrSSe nanosheets have been investigated by using Density Functional Theory (DFT). In order to find the most stable site, two sites (S site and Se site) of the nanosheets have been chosen for gas adsorption. The adsorption energy, charge transfer, work function, and electronic properties have been examined to understand the adsorption behavior. The results show chemisorption for CO, NO, and NO2 gas molecules on ScSSe, at the Sc site with energy -1.52, -1.61 and -1.41 eV respectively. Unlike ScSSe, both TiSSe and ZrSSe show weak physisorption with energy ranges from -0.09 to -0.29 eV, and -0.07 to -0.22 eV respectively. Band structures and Density of States (DOS) indicate the metallic behavior of the nanosheets. Furthermore, the recovery times for CO, NO, and NO2 gas molecules on ScSSe have also been calculated and found that in second range. In the work function calculation, the reduction of work function has been observed after adsorption of CO, NO and NO2 on the ScSSe. Therefore, Janus ScSSe stands out as a promising candidate for detecting CO, NO, and NO2 gas molecules.